here is my simracing H-Shifter, which has been designed as hobby project. It has some flaws, but as for the prototype stage it's quite good and fully operational.
I'm not an electronic so the electronic part is USB joystick board used in arcade machines.
The mechanics involves frame made of stainless steel and aluminium, some springs, and ball bearings.
Here is the render of 3D model:
And some photos:
And bonus - YT movie:
I hope you'll like it. I'm going to design the Rev. v.2 which should be even better.
Oh, and unfortunately - I won't post the 3D data on grabcad - it has too much potential for me.